WO2023050391A1

WO2023050391A1 - Battery cell, battery, and electric apparatus

Info

Publication number: WO2023050391A1
Application number: PCT/CN2021/122383
Authority: WO
Inventors: 陈世龙; 杨飘飘; 陈小波; 李耀; 胡璐
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2023-04-06
Also published as: CN116391295A; EP4220837A4; JP2023546802A; KR20230061460A; US20230268608A1; EP4220837A1

Abstract

The present application relates to the technical field of battery manufacturing, and relates to a battery cell, a battery, and an electric apparatus. The present application provides a battery cell, comprising: a housing; a pressure relief member, provided on the first wall of the housing; an electrode assembly, provided in the housing; an electrolyte, immersing the electrode assembly; and a packaging member and an active substance, disposed in the housing, wherein the packaging member is used for packaging the active substance at the side of the electrode assembly close to the first wall, the packaging member is configured to release the active substance when the internal pressure or temperature of the battery cell reaches a first threshold, and the active substance can react with the electrolyte and/or the electrode assembly to cause the internal pressure or temperature of the battery cell to rise, so as to actuate the pressure relief member. The battery cell provided by the present application can rapidly release the internal temperature and pressure when thermal runaway occurs, and has good safety performance. The present application further provides a battery and an electric apparatus, comprising the battery cell.

Description

Battery cells, batteries and electrical devices

technical field

The present application relates to the technical field of battery manufacturing, and in particular, to a battery cell, a battery and an electrical device.

Background technique

With the rapid development of the new energy vehicle industry, the technical level of the lithium battery industry is also rapidly improving, and high requirements are placed on the safety performance of battery cells.

When the thermal runaway of the battery cell occurs, the internal temperature and pressure will rise sharply. If the internal temperature and pressure cannot be discharged in time, the battery cell may detonate and cause a serious safety accident.

Contents of the invention

For this reason, the present application proposes a battery cell, a battery and an electrical device, which can quickly release the internal temperature and pressure when the battery cell is thermally runaway, and has better safety performance.

The embodiment of the first aspect of the present application proposes a battery cell, including: a housing; a pressure relief member disposed on the first wall of the housing; an electrode assembly disposed inside the housing; an electrolyte submerging the electrodes assembly; a package and an active material disposed inside the casing, the package is used to package the active material on a side of the electrode assembly close to the first wall, the package is configured activated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold, the active material is capable of reacting with the electrolyte and/or the electrode assembly to cause the The internal pressure or temperature of the battery cell rises, actuating the pressure relief member.

In the battery cell of the embodiment of the present application, the active material is encapsulated near the pressure relief member. When thermal runaway occurs at a certain part inside the battery cell, the package is actuated before the temperature or pressure inside the battery reaches the actuation threshold of the pressure relief part to release the active material, so that a part of the electrode assembly close to the pressure relief part Thermal runaway occurs on the side, the electrode assembly is broken and disassembled, and a large amount of high-temperature and high-pressure gas is produced, so that the temperature or pressure near the pressure relief member rises rapidly to activate the pressure relief member to release the pressure or temperature inside the battery cell. In particular, when the thermal runaway part of the battery cell is far away from the pressure relief part, the release of the active material into the battery cell can ensure that the pressure relief part is effectively actuated when the thermal runaway inside the battery cell occurs, and the battery cell is released smoothly. The pressure or temperature of the battery makes the battery cell have high safety performance.

According to some embodiments of the present application, the pressure relief member is configured to be activated to release the pressure when the internal pressure or temperature of the battery cell reaches a second threshold, the second threshold being greater than the first threshold .

In the above solution, both the pressure relief part and the package are actuated by pressure rupture, and the actuation threshold of the pressure relief part is greater than the actuation threshold of the package, which can reliably realize that the package is actuated before the pressure relief part to pass through The pressing piece releases the pressure inside the battery cell, so that the battery cell has better safety performance.

According to some embodiments of the present application, the active substance is an oxidizing agent.

In the above solution, the oxidizing agent is used to react with the electrode assembly and/or the electrolyte, the reaction is rapid and strong, the electrode assembly can be broken and decomposed, and a large amount of high-temperature and high-pressure gas is produced to ensure the actuation of the pressure relief part, and the heat inside the battery cell can be released. The pressure or temperature of the out-of-control part is discharged smoothly through the pressure relief part.

According to some embodiments of the present application, the active substance includes at least one of potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride and sodium ferrate.

In the above solution, the above-mentioned active material will not react with the casing and the package, and is a common oxidizing agent, which is easy to obtain and low in cost.

According to some embodiments of the present application, the packaging member encapsulates at least a part of the active material at a position corresponding to the pressure relief member.

In the above solution, the active material not only triggers a chemical reaction near the pressure relief member to actuate the pressure relief member, but also triggers a chemical reaction at other positions inside the battery cell to break the electrode assembly at the corresponding position, making the battery cell The exhaust channel from the thermal runaway part to the pressure relief part is unblocked, so as to ensure that the gas generated at the thermal runaway part of the battery cell can be smoothly discharged through the pressure relief part.

According to some embodiments of the present application, the housing is provided with a pressure relief hole, both the pressure relief member and the package cover the pressure relief hole, and the package member is disposed near the pressure relief member On one side of the electrode assembly, the package, the pressure relief member and the wall of the pressure relief hole jointly define a closed space for containing the active material.

In the above solution, the active material is encapsulated in the pressure relief hole, which does not occupy too much space inside the battery cell, thereby maintaining the original energy density of the battery cell; and the active material is released when the package is actuated, and the active material can A chemical reaction is induced at a position close to the pressure relief hole, and the pressure relief member can be activated reliably, so that the battery cell has better safety performance.

According to some embodiments of the present application, both the pressure relief member and the packaging member are sheet-shaped.

In the above solution, both the pressure relief part and the packaging part are sheet-shaped, which can occupy a smaller space in the pressure relief hole, so that there is more space for storing active substances in the pressure relief hole.

According to some embodiments of the present application, the encapsulation is made of an insulating material, and the encapsulation is disposed between the first wall and the electrode assembly to insulate and isolate the electrode assembly from the first wall.

In the above solution, the package is not only used to encapsulate the active material, but also used to insulate and isolate the electrode assembly and the first wall, so that the package integrates the function of insulating and encapsulating the active material, reducing the number of components inside the battery cell, making The battery cell has a compact structure and high energy density.

According to some embodiments of the present application, the package has a first accommodation cavity corresponding to the position of the pressure relief member, and at least a part of the active material is encapsulated in the first accommodation cavity.

In the above solution, when the package is actuated, the active material in the first accommodation chamber can be released, and a chemical reaction is triggered near the pressure relief member, which can reliably actuate the pressure relief member, so that the battery cell has better safety performance.

According to some embodiments of the present application, the first accommodating chamber has a first opening, and the first wall and the pressure relief member jointly close the first opening.

In the above solution, the first wall, the pressure relief part and the packaging part jointly form a closed first accommodation cavity, not only the active material is encapsulated near the pressure relief part, but also the active material can trigger a chemical reaction near the pressure relief part when released. reaction, and easy to realize the encapsulation of active substances.

According to some embodiments of the present application, the first wall is rectangular, and the package further has two second accommodation cavities. Along the length direction of the first wall, the two second accommodation cavities are respectively located at the The two sides of the first storage cavity; a part of the active material is packaged in the first storage cavity, and the other part is packaged in the two second storage cavities.

In the above solution, along the length direction of the first wall, a second accommodation chamber is respectively provided on both sides of the first accommodation chamber, and part of the active material is encapsulated in the second accommodation chamber, and the active material in the second accommodation chamber is When released, it can trigger a chemical reaction at the corresponding position of the electrode assembly, so that the side of the electrode assembly close to the pressure relief part is fully broken, and the exhaust channel from the thermal runaway part of the battery cell to the pressure relief part is kept unblocked.

According to some embodiments of the present application, the second accommodating cavity has a second opening, and the first wall closes the second opening.

In the above solution, the first wall and the encapsulation part together form a closed second accommodating chamber, and when the active substance is released, a chemical reaction can be induced at a corresponding position, and the encapsulation of the active substance is easy to realize.

According to some embodiments of the present application, the housing includes a housing and an end cover, the housing has an opening, the housing includes a side wall and a bottom wall, the bottom wall is disposed opposite to the opening, and the end The cover is connected to the side wall and covers the opening, and the first wall is the end cover, the bottom wall or the side wall.

In the above solution, the first wall is an end cover, a bottom wall or a side wall, and the first wall is provided with a pressure relief member. When thermal runaway occurs at a certain part inside the battery cell, the package is activated before the temperature or pressure inside the battery reaches the actuation threshold of the pressure relief member to release the active material, so that the part of the electrode assembly close to the pressure relief member The chemical reaction is broken and decomposed; and the chemical reaction is accompanied by the generation of a large amount of high-temperature and high-pressure gas, so that the temperature or pressure near the pressure relief part rises rapidly to activate the pressure relief part to release the pressure or temperature inside the battery cell.

The embodiment of the second aspect of the present application provides a battery including the battery cell described in the embodiment of the first aspect of the present application.

Due to the characteristics of the battery cells described in the embodiment of the first aspect of the present application, the battery of the embodiment of the second aspect of the present application also has better safety performance.

The embodiment of the third aspect of the present application provides an electric device, including the battery described in the embodiment of the second aspect of the present application.

Due to the characteristics of the battery described in the embodiment of the second aspect of the present application, the electric device in the embodiment of the third aspect of the present application also has better safety performance.

The embodiment of the fourth aspect of the present application proposes a method for manufacturing a battery cell, including:

providing an enclosure, the first wall of which is provided with a pressure relief member;

Provide electrode assemblies;

providing electrolyte;

An encapsulation for enclosing the active material and an active material are provided, the encapsulation being configured to be actuated to release the active material when an internal pressure or temperature of the battery cell reaches a first threshold , the active material can react with the electrolyte and/or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief member;

The electrode assembly is arranged in the casing, the active material is encapsulated on the side of the electrode assembly close to the first wall by the packaging member, and the electrolyte solution is injected into the casing.

The embodiment of the fifth aspect of the present application proposes a battery cell manufacturing equipment, including:

The first providing device is used to provide a casing, the first wall of the casing is provided with a pressure relief member;

a second providing device for providing an electrode assembly;

a third providing device for providing electrolyte;

The fourth providing device is used for providing a package and an active material, the package is used to package the active material, and the package is configured to trigger the battery when the internal pressure or temperature of the battery cell reaches a first threshold. to release the active material capable of reacting with the electrolyte and/or the electrode assembly to increase the internal pressure or temperature of the battery cell thereby actuating the pressure release pieces;

The installation module is used to arrange the electrode assembly in the casing, use the packaging member to encapsulate the active material on the side of the electrode assembly close to the first wall, and inject the electrolyte inside the housing.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

What Fig. 1 shows is a simple schematic diagram of a vehicle in an embodiment of the present application;

Fig. 2 shows a schematic structural view of the battery of the vehicle in Fig. 1;

FIG. 3 shows a schematic structural view of a battery cell in a first form of some embodiments of the present application;

Fig. 4 is a schematic structural view showing that the end cap of the battery cell in Fig. 3 is connected with an electrode terminal, a pressure relief member and a package;

Fig. 5 is A-A sectional view among Fig. 4;

FIG. 6 shows a schematic structural view of a battery cell in a second form of some embodiments of the present application;

FIG. 7 is a schematic structural diagram of the end cap of the battery cell in FIG. 6 connected with an electrode terminal, a pressure relief member and a package;

Fig. 8 is the B-B sectional view among Fig. 7;

Fig. 9 is a partial enlarged view of position C in Fig. 8 (embodying the first accommodating cavity of the first form).

FIG. 10 shows a schematic structural view of the second form of the first accommodation cavity of the battery cell in FIG. 6;

FIG. 11 shows a schematic structural view of a third form of the first accommodation cavity of the battery cell in FIG. 6;

FIG. 12 is a schematic structural diagram of a package corresponding to the first accommodation cavity of the third form of the battery cell in FIG. 11 .

Figure 13 is a partial enlarged view at D in Figure 8;

The above figures are not presented to scale.

Icons: 1000-vehicle; 100-battery; 10-battery unit; 11-shell; 111-shell; 1111-bottom wall; 1112-side wall; 112-end cover; 1121-pressure relief hole; 11211-hole wall 1122-first side; 1123-second side; 1124-first part; 1125-second part; 1126-closed space; 113-opening; Pressing piece; 14-electrode terminal; 15-package; 151-first groove; 1512-first accommodation cavity; 1513-storage part; 152-second groove; 154-support part; 155-exhaust space; 16-active material; 20-box; 21-first box; 22-second box; 200-controller; 300-motor.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are the Claim some of the examples, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field of this application; the terms used in this application in the description of the application are only to describe specific implementations The purpose of the example is not intended to limit the present application; the terms "comprising" and "having" in the specification and claims of the present application and the description of the above drawings, as well as any variations thereof, are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the description and claims of the present application or the above drawings are used to distinguish different objects, rather than to describe a specific sequence or primary-subordinate relationship.

Reference in this application to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The occurrences of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is understood explicitly and implicitly by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

What needs to be explained in the description of this application is that the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense unless otherwise clearly specified and limited, for example, it can be a fixed connection or a Detachable connection, or integral connection; can be directly connected, can also be indirectly connected through an intermediary, and can be internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

"Plurality" in this application refers to two or more (including two).

In the present application, the battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, which are not limited in the embodiments of the present application. The battery cell can be in the form of a cylinder, a flat body, a cuboid or other shapes, which is not limited in this embodiment of the present application. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and pouch battery cells.

The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack, and the like. A battery generally includes a box for encapsulating one or more battery cells, and the box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.

The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive pole piece, a negative pole piece and a separator. A battery cell works primarily by moving metal ions between the positive and negative pole pieces. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the positive electrode collector without the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. Fluid, the positive electrode current collector not coated with the positive electrode active material layer is used as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode collector without the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. Fluid, the negative electrode current collector not coated with the negative electrode active material layer is used as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current is passed without fusing, the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together. The material of the isolation film may be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene). In addition, the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiment of the present application.

The battery cell also includes a pressure relief member that is actuated when the internal pressure of the battery cell reaches a threshold. Threshold design varies according to design requirements. The threshold may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte and separator of the battery cell. The pressure relief member may take the form of an explosion-proof valve, gas valve, pressure relief valve or safety valve, etc., and may specifically adopt a pressure-sensitive or temperature-sensitive element or configuration, that is, when the internal pressure or temperature of the battery cell reaches a threshold , the pressure relief member performs an action or the weak structure provided in the pressure relief member is destroyed, thereby forming an opening or passage for internal pressure or temperature release.

The "actuation" mentioned in this application means that the pressure relief member acts or is activated to a certain form, so that the internal pressure and temperature of the battery cells can be released. Actions by the pressure relief member may include, but are not limited to, at least a portion of the pressure relief member rupture, crumble, be torn, or open, among others. When the pressure relief member is actuated, the high-temperature and high-pressure material inside the battery cell will be discharged from the opened part as discharge. In this way, the pressure and temperature of the battery cells can be released under the condition of controllable pressure or temperature, so as to avoid potential more serious accidents.

In the related art, when thermal runaway occurs inside the battery cell, the pressure or temperature inside the battery cell begins to rise, and when the pressure or temperature inside the battery cell rises to a threshold value that causes the pressure relief member to activate, the pressure relief member At least a part of the battery cell is broken, broken, torn or opened, and the high-temperature and high-pressure material inside the battery cell is discharged from the opened part, thereby avoiding potential more serious accidents.

The inventor found through research that when the thermal runaway part of the battery cell is far away from the pressure relief part, for example, when the thermal runaway part is located on the side of the electrode assembly away from the pressure relief part, the reaction force generated by the thermal runaway will push the electrode assembly Move toward the pressure relief part to block the pressure relief part, so that the pressure relief part cannot be actuated effectively, and the high temperature and high pressure gas inside the battery cell cannot be discharged from the pressure relief part, thus causing the battery cell to deflagrate.

Based on the above idea, this application proposes a new technical solution, which can effectively actuate the pressure relief part when the thermal runaway part is far away from the pressure relief part, and quickly release the pressure or temperature inside the battery cell, so that the battery cell The body has high safety performance.

It can be understood that the battery cells described in the embodiments of the present application can directly supply power to electric devices, and can also be connected in parallel or in series to form batteries to supply power to various electric devices in the form of batteries.

It can be understood that the electric devices that use battery cells or batteries described in the embodiments of the present application can be in various forms, for example, mobile phones, portable devices, notebook computers, battery cars, electric cars, ships, spacecraft, Electric toys and electric tools, etc. For example, spacecraft include airplanes, rockets, space shuttles and spaceships, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric boat toys and Electric aircraft toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and planer.

The battery cells and batteries described in the embodiments of the present application are not limited to the above-described electric devices, but also applicable to all electric devices using battery cells and batteries. However, for the sake of brevity, the following embodiments All electric vehicles are taken as an example for illustration.

FIG. 1 shows a simplified schematic diagram of a vehicle in an embodiment of the present application, and FIG. 2 shows a schematic structural diagram of a battery of the vehicle in FIG. 1 .

As shown in FIG. 1 , a battery 100 , a controller 200 and a motor 300 are disposed inside the vehicle 1000 , for example, the battery 100 may be disposed at the bottom, front or rear of the vehicle 1000 . The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle.

In some embodiments of the present application, the battery 100 can be used for power supply of the vehicle 1000 , for example, the battery 100 can be used as an operating power source of the vehicle 1000 . The controller 200 is used to control the power supply of the battery 100 to the motor 300 , for example, for starting, navigating, and working power requirements of the vehicle 1000 during driving.

In other embodiments, the battery 100 can not only be used as an operating power source for the vehicle 1000 , but can also be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel oil or natural gas to provide driving power for the vehicle 1000 .

Wherein, the battery 100 mentioned in the embodiment of the present application refers to a single physical module including one or more battery cells 10 to provide higher voltage and capacity. For example, the battery 100 is formed by connecting multiple battery cells 10 in series or in parallel.

As shown in FIG. 2 , the battery 100 includes a plurality of battery cells 10 and a case 20 , and the plurality of battery cells 10 are placed in the case 20 . The box body 20 includes a first box body 21 and a second box body 22 . The first box body 21 and the second box body 22 are closed together to form a cavity of the battery 100 , and a plurality of battery cells 10 are placed in the battery cavity. Wherein, the shapes of the first box body 21 and the second box body 22 may be determined according to the combined shapes of the plurality of battery cells 10 , and each of the first box body 21 and the second box body 22 may have an opening 113 . For example, both the first box body 21 and the second box body 22 can be hollow cuboids and only one face is an opening face, the openings 113 of the first box body 21 and the second box body 22 are arranged oppositely, and the first box body 21 Interlock with the second box body 22 to form a box body 20 with a closed chamber. A plurality of battery cells 10 are connected in parallel or connected in series or mixed and placed in the box 20 formed by fastening the first box 21 and the second box 22 .

FIG. 3 is a schematic structural view of a battery cell in a first form according to some embodiments of the present application.

As shown in FIG. 3 , the battery cell 10 includes a casing 11, an electrode assembly 12, a pressure relief member 13, two electrode terminals 14, and two current collecting members (not shown in the figure), and the casing 11 includes a casing 111 and a terminal The cover 112 , the housing 111 includes a side wall 1112 and a bottom wall 1111 , the bottom wall 1111 is disposed opposite to the opening 113 , and the end cover 112 is connected to the side wall 1112 and covers the opening 113 . The electrode assembly 12 and the electrolyte are disposed inside the shell 11, and the electrode assembly 12 is immersed in the electrolyte.

The housing 111 may be hexahedral, cylindrical or elliptical. The housing 111 may be made of metal material, such as aluminum, aluminum alloy, or nickel-plated steel. The size and shape of the end cap 112 matches the opening 113 of the casing 111 , and the end cap 112 is fixed to the opening 113 of the casing 111 , so as to seal the electrode assembly 12 and the electrolyte in the cavity of the casing 111 . The end cap 112 is made of metal materials, such as aluminum, steel and other materials. The end cap 112 is provided with two electrode lead-out holes, and the two electrode terminals 14 are disposed in the two electrode lead-out holes of the end cap 112 . Of the two electrode terminals 14 , one is a positive electrode terminal and the other is a negative electrode terminal.

In some embodiments of the present application, the length direction of the housing 111 extends along the first direction X, the height direction extends along the second direction Z, and the thickness direction extends along the third direction Y. The opening 113 of the housing 111 is connected to the bottom wall 1111 oppositely arranged along the second direction Z. The end cover 112 is rectangular, the length direction of the end cover 112 extends along the first direction X, the width direction extends along the third direction Y, the thickness direction extends along the second direction Z, the first direction X, the second direction Z and the third direction Y are perpendicular to each other.

In other embodiments, the housing 111 can also be a cylinder or an elliptical cylinder whose axis extends along the second direction Z, and the size and shape of the end cap 112 matches the opening 113 of the housing 111 .

The electrode assembly 12 includes a main body 121 and two pole tabs 122 , one of which is a positive pole tab 122 and the other is a negative pole tab 122 . The main body 121 includes a positive electrode piece, a negative electrode piece and a separator, and the separator is located between the positive electrode piece and the negative electrode piece to separate the positive electrode piece from the negative electrode piece. Among the two tabs 122 , one is the tab 122 of the positive pole, and the other is the tab 122 of the negative pole. The positive electrode terminal 14 is electrically connected to the positive electrode lug 122 through a current collecting member, and the negative electrode terminal 14 is electrically connected to the negative electrode lug 122 through another current collecting member.

In some embodiments of the present application, the battery cell 10 includes two electrode assemblies 12, and the two electrode assemblies 12 are stacked along the third direction Y, and each electrode assembly 12 includes a main body 121 and two electrodes with different polarities. The tabs 122 of the same polarity of the two electrode assemblies 12 are connected to a corresponding electrode terminal 14 through the same current collecting member. In other embodiments, the battery cell 10 may also include only one electrode assembly 12 , or include other numbers of electrode assemblies 12 stacked.

In some embodiments of the present application, the two tabs 122 with different polarities are located on the side of the main body 121 close to the end cover 112 . In other embodiments, two tabs 122 with different polarities may be located on both sides of the main body 121 along the first direction X, or located on the side of the main body 121 away from the end cover 112 along the second direction Z; The tabs 122 with different polarities can also be located on both sides of the main body 121 along the second direction Z.

The pressure relief member 13 is disposed on the housing 11 , and the pressure relief member 13 is used to activate when the internal pressure or temperature of the battery cell 10 reaches a second threshold, so that the internal pressure and temperature of the battery cell 10 can be released. The second threshold may be a temperature threshold or a pressure threshold. The pressure relief member 13 can be disposed on the bottom wall 1111 or the side wall 1112 of the casing 111 , and can also be disposed on the end cover 112 .

As shown in FIG. 3 , in some embodiments of the present application, a pressure relief hole 1121 is provided at the central position of the end cover 112 along the first direction X, and the pressure relief member 13 is disposed in the pressure relief hole 1121 . The two electrode terminals 14 are respectively disposed on two sides of the pressure relief hole 1121 along the first direction X. In other embodiments, depending on the shape of the battery cell 10 , the end cap 112 can also be in other shapes, such as circular or oval, and the electrode terminals 14 and the pressure relief member 13 can also be arranged in other ways.

As shown in FIG. 3, in the battery cell 10 of some embodiments of the present application, the battery cell 10 includes a casing 11, a pressure relief member 13, an electrode assembly 12, an electrolyte (not shown in the figure), a package 15 and Active material 16 (please refer to FIG. 5). The electrode assembly 12 is disposed inside the shell 11 , the electrode assembly 12 is immersed in the electrolyte, and the pressure relief member 13 is disposed on the first wall of the shell 11 . The package 15 and the active material 16 are disposed inside the casing 11, the package 15 is used to package the active material 16 on the side of the electrode assembly 12 close to the first wall, and the package 15 is arranged inside the battery cell 10 When the pressure or temperature reaches a first threshold, the active material 16 is activated to release the active material 16, and the active material 16 can react with the electrolyte and/or the electrode assembly 12 to increase the internal pressure or temperature of the battery cell 10, thereby actuating the release. Compression piece 13.

The first wall can be located on the side wall 1112 or the bottom wall 1111 of the casing 111 , or can be located on the end cover 112 . That is to say, the pressure relief member 13 can be located on the side wall 1112 , the bottom wall 1111 or the end cover 112 .

The first wall is provided with a pressure relief hole 1121 , and the pressure relief member 13 is connected to the first wall and covers the pressure relief hole 1121 . The pressure relief member 13 may be arranged at the center of the first wall, or at a portion near the edge of the first wall. There are many ways to actuate the pressure relief member 13. It can be broken when the internal pressure of the battery cell 10 reaches the second threshold to release the pressure or temperature inside the battery cell 10, or it can be reached when the internal temperature of the battery cell 10 reaches the second threshold. The second threshold is melted to release the pressure or temperature inside the battery cell 10 .

When the package 15 is actuated, the active substance 16 can be completely released near the pressure relief member 13, or partly released near the pressure relief member 13, and partly released at other locations.

The manner in which the encapsulation member 15 encapsulates the active substance 16 can have various implementation forms. The package 15 can form a closed space together with the first wall and the pressure relief member 13 to encapsulate the active material 16. The inside of the package 15 can also have a hollow closed space, and the active material 16 can be packaged by composite injection molding. Inside the package 15. The active material 16 can completely fill the above-mentioned closed space, or can partially fill the above-mentioned closed space.

The encapsulating member 15 may be an independently provided component for encapsulating the active material 16 , or it may be a structural improvement of the original components inside the battery cell 10 to realize the function of encapsulating the active material 16 in order to realize insulation and sealing.

The actuation manner of the package 15 has various implementation forms, and the first threshold may be a pressure threshold or a temperature threshold. The package 15 can be broken to release the active material 16 when the internal pressure of the battery cell 10 reaches a first threshold, or melted to release the active material 16 when the internal temperature of the battery cell 10 reaches a first threshold.

The active material 16 can be liquid, solid or powder; the active material 16 can be a material that chemically reacts with the electrolyte, or a material that chemically reacts with the electrode assembly 12, or a material that reacts with the electrolyte and the electrode assembly. 12 Substances that undergo chemical reactions. The active material 16 may be an oxidant, or other substances capable of chemically reacting with the electrolyte and/or the electrode assembly 12 to generate a large amount of high temperature and pressure and break the electrode assembly 12 .

In the battery cell 10 of the embodiment of the present application, an active material 16 is encapsulated near the pressure relief member 13 . When thermal runaway occurs in a certain part inside the battery cell 10, the packaging member 15 is activated before the temperature or pressure inside the battery 100 reaches the actuation threshold of the pressure relief member 13, so as to release the active material 16, so that the electrode assembly 12 Thermal runaway occurs on the side close to the pressure relief member 13, the electrode assembly is broken and decomposed, and a large amount of high-temperature and high-pressure gas is generated, so that the temperature or pressure near the pressure relief member 13 rises rapidly to activate the pressure relief member 13 to release the battery cell 10 internal pressure or temperature. In particular, when the thermal runaway part of the battery cell 10 is far away from the pressure relief member 13, releasing the active material 16 into the battery cell 10 can ensure effective actuation of the pressure relief member 13 when thermal runaway occurs inside the battery cell 10, The pressure or temperature inside the battery cell 10 is released smoothly, so that the battery cell 10 has higher safety performance.

As shown in FIG. 3 , in some embodiments of the present application, the housing 11 includes a housing 111 and an end cover 112, the housing 111 has an opening 113, the housing 111 includes a side wall 1112 and a bottom wall 1111, and the bottom wall 1111 and the opening 113 is opposite to each other. The end cover 112 is connected to the side wall 1112 and covers the opening 113 . The first wall is the end cover 112 , the bottom wall 1111 or the side wall 1112 .

Specifically, the bottom wall 1111 is opposite to the opening 113 along the second direction Z, the thickness direction of the end cover 112 extends along the second direction Z, and the end cover 112 is connected to the edge of the side wall 1112 away from the bottom wall 1111 and covers the opening 113 , so as to seal the electrode assembly 12 inside the casing 11 .

It can be understood that the positions of the bottom wall 1111 , the side wall 1112 and the end cover 112 are related to the placement state of the battery cell 10 .

In some embodiments of the present application, the second direction Z extends vertically, the battery cell 10 is placed upright, the first wall is the end cover 112, the pressure relief hole 1121 is set upward, and the pressure relief member 13 is located on the battery cell. On the upper side of the body 10 , the bottom wall 1111 is located on the bottom side of the battery cell 10 . When thermal runaway occurs inside the battery cell 10, the thermal runaway site may be located inside the electrode assembly 12, or may be close to the surface of the electrode assembly 12; Located near the end cap 112. In particular, when thermal runaway occurs at the position of the electrode assembly 12 close to the bottom wall 1111 , the exhaust passage from the side of the electrode assembly 12 close to the bottom wall 1111 to the pressure relief member 13 is not smooth. The package 15 is actuated in advance before the actuation, which can prevent the electrode assembly 12 from being pushed up under the action of partial air pressure, and the top of the electrode assembly 12 is attached to the end cap 112 to seal the pressure relief hole 1121, causing the pressure relief member 13 to fail. effective actuation.

In other embodiments, according to the placement state of the battery cell 10 and the arrangement position of the first wall, the pressure relief hole 1121 can be opened in the horizontal direction or set downward, and the package 15 is activated in advance to release the active material 16, which can ensure The pressure relief member 13 is effectively actuated.

In the above solution, the first wall is the end cover 112 , the bottom wall 1111 or the side wall 1112 , and the first wall is provided with the pressure relief member 13 . When thermal runaway occurs in a certain part inside the battery cell 10, the packaging member 15 is activated before the temperature or pressure inside the battery 100 reaches the actuation threshold of the pressure relief member 13, so as to release the active material 16, so that the electrode assembly 12 The part close to the pressure relief member 13 is broken and decomposed under the chemical reaction; and the chemical reaction is accompanied by a large amount of high temperature and high pressure gas, so that the temperature or pressure near the pressure relief member 13 rises rapidly to activate the pressure relief member 13 to release the battery cell 10 internal pressure or temperature.

In some embodiments of the present application, the pressure relief member 13 is configured to be activated to release the pressure when the internal pressure or temperature of the battery cell 10 reaches a second threshold, the second threshold being greater than the first threshold.

There are many specific implementation forms for activating the pressure relief member 13 when the internal pressure of the battery cell 10 reaches the second threshold. The pressure relief member 13 can be a metal sheet with notches on the surface, or a polymer film with a locally thinned thickness. When the internal pressure of the battery cell 10 reaches the second threshold, the scratch or the locally thinned area ruptures to release the battery cell. The pressure inside the battery cell 10; the edge of the pressure relief member 13 can be bonded to the first wall, or can be pressed against the first wall with a seal, etc. When the internal pressure of the battery cell 10 reaches the second threshold, the pressure relief member 13 The edge is separated from the first wall to release the pressure inside the battery cell 10 .

In other embodiments, the pressure relief member 13 can also be actuated when the internal temperature of the battery cell 10 reaches an actuation threshold, and the actuation temperature threshold of the pressure relief member 13 is higher than that inside the battery cell 10 when the encapsulation 15 is actuated. temperature.

Both the pressure relief component 13 and the package 15 are actuated by pressure breakers, and the actuation threshold of the pressure relief component 13 is greater than the actuation threshold of the package 15, so that the package 15 can be reliably actuated before the pressure relief component 13 to pass The pressure relief member 13 releases the pressure inside the battery cell 10 , so that the battery cell 10 has better safety performance.

In some embodiments of the present application, active material 16 is an oxidizing agent.

The oxidizing agent can react with the electrolyte and/or the pole pieces in the electrode assembly 12 to generate a large amount of high-temperature and high-pressure gas and break the pole pieces.

The oxidant is used to react with the electrode assembly 12 and/or the electrolyte, the reaction is rapid and strong, the electrode assembly 12 can be broken and decomposed and a large amount of high-temperature and high-pressure gas is produced, the pressure relief member 13 can be actuated, and the thermal runaway inside the battery cell 10 can be prevented The pressure or temperature of the part is discharged through the pressure relief member 13 smoothly.

In some embodiments of the present application, the active material 16 includes at least one of potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride and sodium ferrate.

The active material 16 can be a single type of oxidant, or a mixture of multiple oxidants. When the active materials 16 are stored separately in different storage chambers, the active materials 16 in different storage chambers may be the same or different.

The above-mentioned active material 16 will not react with the casing 11 and the package 15 , and is a common oxidizing agent, which is easy to obtain and low in cost.

In some embodiments of the present application, the encapsulation member 15 encapsulates at least a part of the active material 16 at a position corresponding to the pressure relief member 13 .

The active material 16 can be completely encapsulated in the position corresponding to the pressure relief member 13; a part of the active material 16 can also be encapsulated in a position corresponding to the pressure relief member 13, so as to trigger the chemical reaction of the part of the electrode assembly 12 close to the pressure relief member 13, The other part is packaged in other positions of the electrode assembly 12 close to the first wall, and is used to trigger chemical reactions in other positions of the electrode assembly 12 close to the first wall.

The active material 16 not only triggers a chemical reaction at a position near the pressure relief member 13 to actuate the pressure relief member 13, but also induces a chemical reaction at other positions inside the battery cell 10 to break the electrode assembly 12 at the corresponding position, so that the battery cell 10 The exhaust channel from the thermal runaway part of the battery cell 10 to the pressure relief part 13 is unblocked, so as to ensure that the gas generated at the thermal runaway part of the battery cell 10 can be discharged through the pressure relief part 13 smoothly.

FIG. 4 is a schematic diagram of the structure in which the end cap of the battery cell in FIG. 3 is connected with an electrode terminal, a pressure relief member and a package; FIG. 5 is a cross-sectional view of A-A in FIG. 4 .

As shown in Figure 4 and Figure 5, in some embodiments of the present application, the housing 11 is provided with a pressure relief hole 1121, the pressure relief member 13 and the package 15 both cover the pressure relief hole 1121, and the package 15 is arranged on the pressure relief member On the side of 13 close to the electrode assembly 12 , the package 15 , the pressure relief member 13 and the hole wall 11211 of the pressure relief hole 1121 jointly define a closed space for containing the active material 16 .

As shown in FIG. 3 , FIG. 4 and FIG. 5 , based on the aforementioned embodiment of “the first wall is the end cap 112 ”, the two sides of the end cap 112 along the second direction Z are the first side 1122 and the second side 1123 respectively. , the first side 1122 is disposed close to the electrode assembly 12 and located inside the battery cell 10 , and the second side 1123 is located away from the electrode assembly 12 and located outside the battery cell 10 . The pressure relief component 13 is disposed close to the second side 1123 , and the package 15 is disposed close to the first side 1122 . The pressure relief component 13 , the package 15 and the hole wall 11211 of the pressure relief hole 1121 jointly define a closed space.

Along the thickness direction of the end cover 112, the pressure relief member 13 is arranged inside the pressure relief hole 1121, the edge of the pressure relief member 13 is connected to the inner wall of the pressure relief hole 1121, the package 15 is located outside the pressure relief hole 1121, and the package 15 is connected to the surface of the pressure relief hole 1121 close to the first side 1122 .

As shown in FIG. 5 , the end cover 112 also includes a first part 1124 and a second part 1125 , the first part 1124 protrudes from the hole wall 11211 of the pressure relief hole 1121 to the surface of the first wall, and the second part 1125 protrudes from the first side 1122 protrudes from the surface of the first wall. Edges of the pressure relief member 13 are connected to the first part 1124 , and the package 15 is connected to the second part 1125 . The first part 1124 , the second part 1125 , the pressure relief part 13 and the package 15 jointly define a closed space 1126 .

In other embodiments, the pressure relief component 13 and the packaging component 15 have various ways of covering the pressure relief hole 1121 . For example, the pressure relief member 13 and the packaging member 15 are respectively connected to the end cover 112 from the first side 1122 and the second side 1123 of the end cover 112 along the second direction Z; Inside, the area of the package 15 is larger than the area of the pressure relief hole 1121 , the package 15 covers the pressure relief hole 1121 from the first side 1122 of the end cap 112 , and the edge of the package 15 is connected to the surface of the end cap 112 .

The active material 16 is encapsulated in the pressure relief hole 1121, so as not to occupy too much space inside the battery cell 10, thereby maintaining the original energy density of the battery cell 10; and the active material 16 is released when the package 15 is actuated, and the active material 16 can initiate a chemical reaction at a position close to the pressure relief hole 1121 , and can reliably actuate the pressure relief member 13 , so that the battery cell 10 has better safety performance.

As shown in FIG. 5 , in some embodiments of the present application, both the pressure relief member 13 and the packaging member 15 are sheet-shaped.

Both the pressure relief member 13 and the packaging member 15 are sheet-shaped, and can occupy a smaller space in the pressure relief hole 1121 , so that there is more space for storing the active substance 16 in the pressure relief hole 1121 .

FIG. 6 is a schematic structural diagram of a battery cell in a second form according to some embodiments of the present application.

As shown in FIG. 6 , in some embodiments of the present application, the encapsulation 15 is made of an insulating material, and the encapsulation 15 is disposed between the first wall and the electrode assembly 12 to insulate and isolate the electrode assembly 12 from the first wall.

Based on the aforementioned embodiment of “the first wall is the end cap 112 ”, the package is disposed between the end cap 112 and the electrode assembly 12 to insulate and isolate the electrode assembly 12 and the end cap 112 .

The package 15 can be a plastic part that melts when the temperature inside the battery 100 reaches a first threshold to release the active substance 16; the package 15 can also have a local weak spot that breaks when the pressure inside the battery 100 reaches a first threshold. The package 15 also includes via holes corresponding to the electrode lead-out hole and the pressure relief hole 1121 to connect the power supply terminal 14 with the current collecting member, and the pressure relief hole 1121 communicates with the cavity inside the battery cell 10 .

The package 15 is not only used to encapsulate the active material 16, but also used to insulate and isolate the electrode assembly 12 and the first wall, so that the package 15 integrates the function of insulating and encapsulating the active material 16, reducing the number of components inside the battery cell 10, The battery cell 10 has a compact structure and high energy density.

FIG. 7 is a schematic diagram showing the structure of the end cap of the battery cell in FIG. 6 connected with an electrode terminal, a pressure relief member and a package; FIG. 8 is a B-B sectional view in FIG. 7 .

As shown in FIG. 7 and FIG. 8 , in some embodiments of the present application, the package 15 has a first accommodation chamber 1512 corresponding to the position of the pressure relief member 13 , and at least a part of the active material 16 is encapsulated in the first accommodation chamber 1512 Inside.

The active material 16 can be completely packaged in the first storage chamber 1512 , or part of it can be packaged in the first storage cavity 1512 , and the rest can be packaged in other locations.

The first accommodating cavity 1512 may be formed by enclosing the package 15 together with other components, or may exist independently inside the package 15 .

The projection of the pressure relief hole 1121 on the XY plane can fall into the projection of the first accommodation chamber 1512 on the XY plane, so that the active substance 16 released in the first accommodation chamber 1512 can cause chemical reaction in a larger area near the pressure relief member 13. reaction, a large amount of gas is rapidly generated to actuate the pressure relief member 13; it may also be that the projection of the first accommodation chamber 1512 on the XY plane falls into the projection of the pressure relief hole 1121 on the XY plane, or that the first accommodation chamber 1512 is on the XY plane The projection of the pressure relief hole 1121 coincides with the projection of the pressure relief hole 1121 on the XY plane, so as to flexibly arrange the storage position of the active material 16 according to the space inside the battery cell 10, as long as the chemical reaction caused by the active material 16 when the package 15 is actuated produces It is enough that a large amount of gas can actuate the pressure relief member 13.

When the packaging part 15 is actuated, the active substance 16 in the first containing chamber 1512 can be released, and the vicinity of the pressure relief part 13 triggers a chemical reaction, which can reliably actuate the pressure relief part 13, so that the battery cell 10 has better safety performance .

FIG. 9 is a partially enlarged view at point C in FIG. 8 , and FIG. 9 shows a schematic structural view of the first accommodation cavity of the first form of the battery cell in FIG. 6 .

As shown in FIG. 9 , in some embodiments of the present application, the first accommodating chamber 1512 has a first opening, and the first wall and the pressure relief member 13 jointly close the first opening.

Based on the implementation form of "the first wall is the end cover 112", along the first direction X, a first groove 151 is provided in the center of the package 15, and the first groove 151 faces away from the end cover from the surface of the package 15 The direction of 112 is recessed, the inside of the first groove 151 has a first accommodating cavity 1512, the opening 113 on the side of the first groove 151 close to the end cover 112 constitutes the first opening, and the projection of the pressure relief member 13 on the XY plane Falling into the projection of the first groove 151 on the XY plane, the first side 1122 of the end cover 112 is bonded to the package 15 and closes the first opening to form a closed first receiving cavity 1512 .

FIG. 10 is a schematic structural diagram of the second form of the first accommodation cavity of the battery cell in FIG. 6 .

As shown in FIG. 10 , specifically, the middle part of the first groove 151 is further recessed in the direction away from the end cap 112 to form a storage portion 1513, which is used to store the active material 16, so that the vicinity of the pressure relief member 13 corresponds to More active substance 16 is stored. The projection of the storage part 1513 on the XY plane falls into the projection of the pressure relief member 13 on the XY plane, and when the package 15 is actuated, it can preferentially induce a chemical reaction in the vicinity of the pressure relief member 13 and improve the actuation of the pressure relief member 13. speed. The side of the storage part away from the end cap 112 can be used to abut against the surface of the electrode assembly 12, so that both sides of the package 15 abut between the end cap 112 and the electrode assembly 12, so that the battery cell 10 has a compact structure .

FIG. 11 shows a schematic structural view of a third form of the first accommodation chamber of the battery cell package in FIG. 6 ; FIG. 12 shows a schematic structural view of the package in FIG. 11 .

As shown in Figures 11 and 12, in other embodiments, the first housing chamber 1512 may also be a closed space independently formed inside the package 15, and the active material 16 is encapsulated in the first housing chamber 1512 in the form of composite injection molding. internal. Specifically, there is a support portion 154 at the via hole corresponding to the pressure relief hole 1121 of the package 15. The support portion 154 blocks part of the via hole and exposes the space on both sides of the via hole along the first direction X, forming two rows. Air space 155. One side of the support portion 154 is in contact with the pressure relief member 13 so that the two exhaust spaces 155 communicate with the inside of the battery cell 10 . The support portion 154 and the storage portion 1513 of the first groove 151 together form a closed first accommodation chamber 1512 , and the active material 16 is packaged inside the first accommodation chamber 1512 .

The first wall, the pressure relief member 13 and the packaging member 15 jointly form a closed first accommodation cavity 1512, which not only enables the active material 16 to be encapsulated near the pressure relief member 13, but also enables the active material 16 to be in the vicinity of the pressure relief member 13 when released. A chemical reaction is initiated, and the encapsulation of the active material 16 is easy to achieve.

FIG. 13 is a partial enlarged view at D in FIG. 8 .

As shown in Fig. 8 and Fig. 13, in some embodiments of the present application, the first wall is rectangular, and the package 15 also has two second accommodating cavities 1522, along the length direction of the first wall, two second accommodating cavities The cavities 1522 are respectively located on both sides of the first accommodating cavity 1512 ; a part of the active material 16 is packaged in the first accommodating cavity 1512 , and the other part is packaged in the two second accommodating cavities 1522 .

Based on the implementation form of "the first wall is the end cap 112", the end cap 112 is a rectangle whose length direction extends along the first direction X and whose width direction extends along the third direction Y. Along the first direction, the two ends of the package 15 A second accommodating cavity 1522 is respectively provided. The second housing cavity 1522 can be a closed space independently formed inside the package 15, and the active material 16 is packaged inside the second housing cavity 1522 in the form of compound injection; the second housing cavity 1522 can also be a closed space between the package 15 and the The closed space formed by the cover 112 is jointly enclosed.

Along the length direction of the first wall, a second housing cavity 1522 is provided on both sides of the first housing cavity 1512, and a part of the active material 16 is encapsulated in the second housing cavity 1522, and the active material 16 in the second housing cavity 1522 When it is released, it can trigger a chemical reaction at the corresponding position of the electrode assembly 12, so that the side of the electrode assembly 12 close to the pressure relief member 13 is fully broken, and the exhaust passage from the thermal runaway part of the battery cell 10 to the pressure relief member 13 is kept unblocked. .

As shown in FIG. 13 , in some embodiments of the present application, the second accommodating chamber 1522 has a second opening, and the first wall closes the second opening.

Specifically, along the first direction, two ends of the package 15 are respectively provided with a second groove 152, the second groove 152 is formed by indenting the surface of the package 15 toward the direction away from the end cap 112, and the second groove The groove 152 has a second receiving cavity 1522 inside, and the opening 113 of the second groove 152 close to the end cover 112 constitutes a second opening. The packaging component 15 is attached to the end cap 112 to close the second opening to form a closed second receiving cavity 1522 .

The second accommodating chamber 1522 may have the same size as the electrode assembly 12 along the third direction Y, so that the end corners of the electrode assembly 12 on the side close to the end cap 112 in the first direction X are broken and disassembled, so that the electrode assembly 12 The exhaust passage from the thermal runaway part to the pressure relief member 13 is unblocked; the second accommodation cavity 1522 can also be centrally arranged relative to the electrode assembly 12 along the third direction Y.

Specifically, the package 15 is provided with a connection portion 153 abutting against the surface of the electrode assembly 12 along both sides of the first direction X, and the connection portion 153 is formed from the side of the package 15 away from the end cap 112 along the second direction. Z is formed protrudingly, and the second groove 152 is formed inside the connector so that the structure of the package 15 is compact.

The first wall and the packaging member 15 jointly form a closed second receiving cavity 1522 , when the active substance 16 is released, a chemical reaction can be induced at a corresponding position, and the packaging of the active substance 16 is easy to realize.

Some embodiments of the present application propose a battery 100 including the battery cell 10 of some embodiments of the present application.

Due to the characteristics of the battery cell 10 , the battery 100 in some embodiments of the present application also has better safety performance.

Some embodiments of the present application provide an electric device, including a battery 100 .

Due to the characteristics of the battery 100 , the electric device in some embodiments of the present application also has better safety performance.

Some embodiments of the present application propose a method for manufacturing a battery cell 10, including:

providing a housing 11, the first wall of the housing 11 is provided with a pressure relief member 13;

providing an electrode assembly 12;

providing electrolyte;

An encapsulation 15 and an active material 16 are provided, the encapsulation 15 is used to encapsulate the active material 16, the encapsulation 15 is configured to be activated to release the active material 16 when the internal pressure or temperature of the battery cell 10 reaches a first threshold, the active material 16 is capable of reacting with the electrolyte and/or the electrode assembly 12 to increase the internal pressure or temperature of the battery cell 10, thereby actuating the pressure relief member 13;

The electrode assembly 12 is arranged in the casing 11 , the active material 16 is packaged on the side of the electrode assembly 12 close to the first wall by the packaging member 15 , and the electrolyte solution is injected into the casing 11 .

Some embodiments of the present application propose a manufacturing equipment for a battery cell 10, including:

The first providing device is used to provide the housing 11, the first wall of the housing 11 is provided with a pressure relief member 13;

The second providing device is used for providing the electrode assembly 12;

a third providing device for providing electrolyte;

The fourth providing device is used to provide a package 15 and an active material 16, the package 15 is used to package the active material 16, the package 15 is configured to be activated to activate when the internal pressure or temperature of the battery cell 10 reaches a first threshold releasing the active material 16 capable of reacting with the electrolyte and/or the electrode assembly 12 to increase the internal pressure or temperature of the battery cell 10 to actuate the pressure relief member 13;

The installation module is used for disposing the electrode assembly 12 in the casing 11 , encapsulating the active material 16 on the side of the electrode assembly 12 close to the first wall with the package 15 , and injecting the electrolyte into the casing 11 .

As shown in FIG. 3 to FIG. 5 , some embodiments of the present application propose a battery cell 10 , the battery cell 10 includes a casing 111 , an end cap 112 , an electrode assembly 12 , a pressure relief member 13 and a package 15 , and the end The cover 112 is provided with a pressure relief hole 1121, and the upper and lower explosion-proof sheets are arranged at the pressure relief hole 1121, the upper layer of the explosion-proof sheet is the pressure relief piece 13, and the lower layer of the explosion-proof sheet is the package 15. The explosion-proof disk is generally made of metal, such as aluminum, steel, etc., and may also be made of plastic. Active material 16 is added between the upper and lower explosion-proof discs. Active material 16 is generally a strong oxidant, such as potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride, ferric acid Sodium Acid, etc. When the internal thermal runaway of the battery cell slowly produces gas, the internal air pressure reaches the first threshold, which is lower than the opening pressure of the upper explosion-proof plate, and the air pressure inside the battery cell will break through the lower explosion-proof plate, releasing the active material 16 to react with the electrolyte , let the electrode assembly close to the pressure relief part 13 fail, generate a large amount of high-temperature and high-pressure gas, and then further break through the upper explosion-proof plate, release heat and spray out the broken and decomposed pole pieces at the same time, increase the exhaust gap at the pressure relief hole 1121, and keep away from the When the electrode assembly of the pressure relief hole 1121 fails, the failed pole piece can be discharged smoothly, thereby preventing the battery cell 10 from bursting due to the failure of the pressure relief member 13 to open and cause the electrode assembly 12 to rush upwards, resulting in a serious safety accident.

As shown in FIG. 6 to FIG. 13 , some embodiments of the present application propose a battery cell 10 , the battery cell 10 includes a casing 111 , an end cap 112 , an electrode assembly 12 , a pressure relief member 13 and a package 15 , and the end The cover 112 is provided with a pressure relief member 13 . The packaging part 15 is made of lower plastic, and is disposed between the end cap 112 and the electrode assembly 12 . Along the length direction of the end cap 112 (that is, the first direction X), the length of the package 15 is approximately the same as the length of the electrode assembly 12, and the middle and both ends of the package 15 have half-open grooves. The end cap 112 is fitted to seal the active material 16 inside the groove. When the internal gas of the battery cell 10 becomes high temperature, the plastic is melted, the active substance 16 is released to react with the electrode assembly, and the pole piece near the pressure relief hole 1121 is discharged, and the exhaust gap is vacated to prevent the end cover 112 from The casing 111 bursts open.

It should be noted that, in the case of no conflict, features in the embodiments of the present application may be combined with each other.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

A battery cell, characterized in that it comprises:

shell;

a pressure relief member disposed on the first wall of the housing;

an electrode assembly disposed inside the casing;

an electrolyte solution to immerse the electrode assembly;

A package and an active material are disposed inside the casing, the package is used to package the active material on a side of the electrode assembly close to the first wall, and the package is configured to actuating to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold, the active material is capable of reacting with the electrolyte and/or the electrode assembly to make the battery cell The internal pressure or temperature of the body increases, thereby actuating the pressure relief member.
The battery cell according to claim 1, wherein the pressure relief member is configured to be actuated to release pressure when the internal pressure or temperature of the battery cell reaches a second threshold, the second The threshold is greater than the first threshold.
The battery cell according to claim 1 or 2, wherein the active material is an oxidizing agent.
The battery cell according to claim 3, wherein the active material comprises potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride and sodium ferrate at least one of the
The battery cell according to any one of claims 1-4, wherein the encapsulation member encapsulates at least a part of the active material at a position corresponding to the pressure relief member.
The battery cell according to claim 5, wherein the casing is provided with a pressure relief hole, and both the pressure relief member and the package cover the pressure relief hole, and the package is arranged on the A side of the pressure relief member close to the electrode assembly, the package, the pressure relief member and the wall of the pressure relief hole jointly define a closed space for containing the active material.
The battery cell according to claim 6, wherein the pressure relief member and the packaging member are both sheet-shaped.
The battery cell according to claim 5, wherein the package is made of an insulating material, and the package is arranged between the first wall and the electrode assembly to insulate and isolate the electrode assembly from the electrode assembly. the first wall.
The battery cell according to claim 8, wherein the package has a first accommodation chamber corresponding to the position of the pressure relief member, at least a part of the active material is encapsulated in the first accommodation chamber Inside.
The battery cell according to claim 9, wherein the first accommodating cavity has a first opening, and the first wall and the pressure relief member jointly close the first opening.
The battery cell according to claim 9 or 10, wherein the first wall is rectangular, and the package further has two second accommodation cavities, along the length direction of the first wall, two The second accommodating cavity is respectively located on both sides of the first accommodating cavity;

A part of the active material is encapsulated in the first accommodation chamber, and another part is encapsulated in the two second accommodation chambers.
The battery cell according to claim 11, wherein the second receiving cavity has a second opening, and the first wall closes the second opening.
The battery cell according to any one of claims 1-12, wherein the casing comprises a casing and an end cover, the casing has an opening, the casing includes a side wall and a bottom wall, the The bottom wall is arranged opposite to the opening, the end cover is connected to the side wall and covers the opening, and the first wall is the end cover, the bottom wall or the side wall.
A battery, characterized by comprising the battery cell according to any one of claims 1-13.
An electrical device, characterized by comprising the battery as claimed in claim 14.
A method for manufacturing a battery cell, comprising:

providing an enclosure, the first wall of which is provided with a pressure relief member;

Provide electrode assemblies;

providing electrolyte;

An encapsulation for enclosing the active material and an active material are provided, the encapsulation being configured to be actuated to release the active material when an internal pressure or temperature of the battery cell reaches a first threshold , the active material can react with the electrolyte and/or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief member;

The electrode assembly is arranged in the casing, the active material is encapsulated on the side of the electrode assembly close to the first wall by the packaging member, and the electrolyte solution is injected into the casing.
A battery cell manufacturing equipment, characterized by comprising:

The first providing device is used to provide a casing, the first wall of the casing is provided with a pressure relief member;

a second providing device for providing an electrode assembly;

a third providing device for providing electrolyte;

The fourth providing device is used for providing a package and an active material, the package is used to package the active material, and the package is configured to trigger the battery when the internal pressure or temperature of the battery cell reaches a first threshold. to release the active material capable of reacting with the electrolyte and/or the electrode assembly to increase the internal pressure or temperature of the battery cell thereby actuating the pressure release pieces;

The installation module is used to arrange the electrode assembly in the casing, use the packaging member to encapsulate the active material on the side of the electrode assembly close to the first wall, and inject the electrolyte inside the housing.